CRA Result code 31 is coming up on my submittal. How do i fix this?

It did the same thing to me too when I tried filing my nieces taxes for her very first time. 

If this is your first time filing, you will have to print & mail your return. 

If you are using TurboTax Online, select File > Filing Hub* from the left side menu. Then click on "Print & Mail your return(s)" to go to a page where you can download a special version of your return to print off and mail.

*If you don’t see the Filing Hub option under File, then select CRA Online Mail and continue forward from there to get to the Filing Hub.

This Canada Revenue Agency (CRA) webpage has a list of where you can mail your return: Where to mail your paper T1 return